5 signs it's time to look for a new credit card

That's according to CreditCards.com, which surveyed 639 credit cardholders in the U.S. earlier this year. "People are creatures of habit," says Matt Schulz, senior industry analyst for CreditCards.com. "They need a big reason to change."

However, sticking with the same credit card year after year could mean you spend more in interest rates and fees than necessary. Plus, you could be missing out on lucrative rewards and sign-up bonuses.

Randy Hopper, vice president of credit cards for Navy Federal Credit Union, says his institution has been offering credit cards for nearly 30 years. "We still have some of our original cardholders," he says. "We try to make sure a member's card keeps up with the times."

Even though Hopper says Navy Federal offers competitive card terms to longtime members, he agrees that consumers should shop around from time to time. "I think it's always healthy to know what sort of value is out there," he says.

Here are five times when consumers should take a look at what else is available on the market.

[See: What to Do if You've Fallen (Way) Behind on Your Credit Card Payments.]

You've had your card since before the last recession

Schulz says longtime cardholders should start shopping for two reasons: Their credit scores may have increased and interest rates have decreased in the past 10 years. "Chances are, your card's interest rate is too high," he says.

If consumers find that their interest rate is no longer competitive, they may not necessarily have to get a new credit card. Hopper says many card issuers are willing to lower interest rates if it's requested by longtime customers.

You're planning a major purchase

Opening a slew of credit card accounts before applying for a mortgage or car loan is probably not a smart idea since multiple inquiries can drive down a credit score. However, for those planning to put a large purchase on a card, shopping for a lucrative sign-up bonus can be a smart way to save money.

For example, the Chase Freedom Unlimited card currently offers a $150 cash-back bonus to new cardholders who charge $500 in the first three months of opening an account. Someone who is about to make a large purchase could effectively save $150 by charging it to the card. Ideally, consumers should save up for the purchase first and then use that money to pay off the balance immediately. Otherwise, interest charges could negate the savings.

Cardholders should also check for annual fees, however, which can offset the value of sign-up bonuses. Some card issuers may waive this fee for the first year, but others charge it immediately, making it impossible to avoid.

You're ready to finally start saving for [insert life goal here]

Whether you plan to see the world or renovate the house of your dreams, you should have the right credit card in your pocket.

"We're seeing unprecedented sign-up bonuses," Schulz says. That means it's easier to rack up the points needed to take a once-in-a-lifetime trip, book a swanky hotel or redeem for gift cards and merchandise. Even those who want cash back rather than points will find plenty of new card offers that can save them money in the pursuit of their life goal.

[See: 10 Foolproof Ways to Reach Your Money Goals.]